Synthetic resins, such as epoxy resins, polyester resins and the like, are commonly used as adhesives for bonding two substrates together. However, synthetic resins are also combined with appropriate substrates, such as fibers, glass, metals and wood, to form composite materials. Such composite materials find application in a variety of fields and industries. For example, synthetic resin-based composite materials are used in the aerospace industry to form parts, propellers, tails, wings and fuselages.
Composite materials typically are formed by preparing the synthetic resin (e.g., mixing a polymer with a catalyst), combining the substrate with the synthetic resin, molding the substrate and resin mixture into the desired shape, and curing the molded substrate and resin mixture until it achieves the desired physical properties. Once cured, the resulting composite material may be removed from the mold, at which point it is ready for use, packaging or further processing.
Common molding techniques include vacuum bag molding, pressure bag molding and autoclave molding. In vacuum bag molding, a mold or form, such as a two-sided mold, is filled with the substrate and resin mixture and placed into a vacuum bag. Then, a vacuum is drawn in the vacuum bag to urge the substrate and resin mixture into the various nooks and crannies of the mold. The vacuum bag is then sealed and cured.
Various techniques have been presented for curing synthetic resin. Most commonly, heat is used to cure resins. For example, sealed vacuum bags may be cured in an oven for a predetermined amount of time. However, alternative techniques for curing synthetic resins include the application of high pressure, whether alone or in combination with heat, as well as exposure to ultraviolet light.
Despite the advances in the field of synthetic resin curing and composite material formation, those skilled in the art continue to seek new techniques for curing synthetic resins and forming composite materials.